In the high speed production or forming of cans or cups drawn from sheet metal, for example, as disclosed in U.S. Pat. Nos. 4,454,743 and No. 4,483,172, it is common to remove the drawn cups from a space defined between the lower die shoe and the press bed with an endless belt conveyor, as shown in the patents. The belt conveyor extends into a tunnel defined within the lower die shoe, and the discharge end of the conveyor is usually driven by a variable speed drive.
One of the problems encountered with using endless conveyors for removing the cups, is the occasional jamming of a group of cups on the conveyor, especially when attempts are made to operate the press at a higher speed. When the cups jam, it is necessary to stop the press and remove the cup jam. This results in down-time for the press and thus reduces the press operating efficiency. In addition, the endless belt conveyors require periodic maintenance in order to repair or replace worn pulleys, drive shafts, bearings, belts or conveyor gear boxes.
To avoid the above mentioned problems associated with mechanical endless belt conveyors for removing drawn cups from the forming press, a high pressure air jet, discharged from a nozzle connected to an air compressor line, has been used to blast each cup from the cup receiving zone and onto an air flotation platform. The platform is provided with closely spaced small holes through which air flows upwardly from a chamber below to provide air floatation for each cup as it is blasted by the high pressure jet of air from the nozzle. However, it has been found that use of a jet of compressed air at each forming station requires the operation of an air compressor which adds significantly to the cost of operating the press. In addition, the small holes in the air floatation platform will clog with lubricating oil which is discharged with the formed cups, and a drop in air floatation can result in a cup jam and down-time for the press.